1. Field of the Invention
The present invention relates to a drum type washing machine, and more particularly, to a structure of a driving unit in a drum type washing machine.
2. Background of the Invention
In general, a drum type washing, making washing by using friction between a drum rotated by a motor and laundry in a state detergent, washing water, and the laundry are introduced into the drum, provides effects of beating and rubbing washing, but gives almost no damage to the laundry, and shows no entangling of the laundry. A structure of a related art drum washing machine will be explained with reference to FIG. 1. FIG. 1 illustrates a longitudinal section of a related art drum type washing machine, provided with a tub 2 mounted inside of a cabinet 1, a drum 3 rotatably mounted on a central portion of inside of the tub 2. There is a motor 5a under the tub 2 connected with a pulley 18. There is a drum shaft 25 connected to a rear of the drum 3, to which a drum pulley 19 is coupled. And, the drum pulley 19 on the drum shaft and the motor pulley 18 connected to the motor 5a are connected by a belt 20 for transmission of power. And, there is a door 21 in a front part of the cabinet 1, with a gasket 22 between the door 21 and the tub 2. There is a hanging spring 23 between an inside of an upper portion of the cabinet 1 and an outside of an upper portion of the tub 2, and a friction damper 24 between an inside of a lower portion of the cabinet 1 and a lower side of an outside of the tub 2 for damping vibration of the tub 2 generated during spinning. There is a detergent container 26 in the upper front of the cabinet 1, and in the upper back of the cabinet 1 is a water supply valve 27 for supplying water to the detergent container.
However, the related art washing machine has the following disadvantages since driving power of the motor 5a is transmitted to the drum 3 through the motor pulley 18, and the drum pulley 19, and the belt 20 connecting the motor pulley 18 and the drum pulley 19.
First, there is a loss of energy in a course of driving power transmission because the driving power is transmitted from the motor 5a to the drum 3, not directly, but through the belt 20 wound around the motor pulley 18 and the drum pulley 19.
And, the driving power transmission from the motor 5a to the drum 3, not directly, but through many components, such as the belt 20, the motor pulley 18, and the drum pulley 19, causes much noise in the course of power transmission.
The lots of components required for transmission of driving power from the motor 5a to the drum 3, such as the motor pulley 18, the drum pulley 19 and the belt 20, require many assembly man-hours. And, the more the number of components required for transmission of driving power from the motor 5a to the drum 3, the more number of spots which require repair, and the more frequent at which repair required. The imbalance caused by the motor mounted to a lower part of rear of the tub 2 causes heavy vibration when the motor is rotated. Consequently, there is a weight balancer of metal or cement separately provided to an opposite position of the motor for system balancing.
In summary, the indirect driving power transmission from the motor 5a to the drum 3 through the motor pulley, the drum pulley, and the belt requires many repair, has much noise, waste of energy, and results in a deterioration of a washing capability.